Glass fabric



e. SLAYTER El AL GLAS S FABRIC Filed June .22, 1957 2 Sheets-Sheet lINVENTOR Fame: Slag/fer Jain H Thomas.

A TTORNEYS.

GLASS FABRIC Filed June 22, 1937 2 Sheets-Sheet 2 5522755 5125/2 51",Jmimfi 1 15517755 IN VEN TORA',

A TTORNEYS.

Patented Oct. 11, 1938 GLASS FABRIC I Games Slayter and John H; Thomas,Newark,

Ohio, assignors to Owens-Illinois Glass Company, a corporation of Ohio IApplication June 22," 1937, Serial No. 149,672

7- Claims. (Cl. ll'L-SZ) The present invention relates to glass textilefabrics, and more. particularly to improved knitted, woven, and braidedfabrics, or the like, which are extremely strong, flexible, and may befolded and flexed a great many times without materially injuring thesame. Thus the present invention relates to a textile material composedof fine glass fibers having improved properties and qualities, renderingthem extremely useful in the 10 arts.

Heretofore it has been attempted to produce interwoven fabrics usingglass filaments, but these fabrics were extremely limited in theirusefulness and in their properties.

formed were, relatively stiff and resisted fiexure.

If the fabrics were folded or creased, they would break apart at thefold, and if they were flexed back and forth for a relatively smallnumber of times, they would break apart. It has even been attempted toproduce a garment using a fabric composed of glass filaments, but inorder to piece the material together, it was necessary to secure it to abacking cloth of organic fibrous material. Another serious disadvantageoi the prior fab- :5 rics composed of glass fibers, was that they werebrash and irritated the skin to an unbearable degree. We aim to overcomethese objections and to largely, if not entirely eliminate brashinessand irritation from our fabrics.

Another defect of the prior art, was the fact that the textile materialscomposed of glass fibers heretofore in use could not be processedthrough the ordinary and conventional textile machines such as windingand spinning machines and .3 through the conventional loom. In order tofabricate glass fabrics in a practical commercial manner, it isnecessary to process them through a conventional machine loom, and thepresent invention provides a glass textile which may be processedthrough the conventional textile machine operations, to produce a fine,high quality piece of merchandise.

One of the serious objections heretofore found in attempting to weaveyarns composed of glass fibers in a conventional loom, was thedifficulty caused by the relative non-elongation of glass fibers ortheir lack of elasticity.

It is an object of the invention to provide a textile material which maybe wholly composed of glass fibers; such material to have strength,flexibility, foldability, and substantial freedom from brashiness orirritation so that it will find commercial uses in many of the arts. Inthus fabricating the textile materials, we also aim to produce yarns,threads, ply yarns, intertwisted yarns,

The fabrics heretofore and cables composed, if desired, wholly of glassfibers, these yarns and threads being of suilicient strength,elasticity, and yieldability that they may be processed through theordinary and conventional textile machine into interwoven, 5 knitted,braided or other types of textile fabrics as desired.

An important phase of the present invention is the provision of fibershaving a fineness below a critical diameter which we have found to be in10 the neighborhood of about .0004 inch in diameter,

and preferably below about .0002 inch in diameter. If the fibers areabove this critical diameter, the fibers are too brittle and coarse topermit them to be intertwisted into yarns, without resorting 15 tospecial and highly expensive means such as a high degree of sizing, andspecial machinery which would seriously limit the commercial andpractical value of the yarns. Even when such expedients are resorted to,the fibers cannot be 20 intertwisted to a sufllciently high degree torender them thoroughly practical in the art. The fibers break andproject out of the yarn and the resulting fabric in a bristly manner sothat handling thereof causes a serious irritation to the skin. 25

We have also found that the fiber diameter is extremely important fromanother point of view, that is, the increased flexibility produced byusing a very fine fiber diameter. Fabrics, properly made up, may beextremely flexible, even limp 30 and soft, if the diameter of theindividual fibers is below the critical range.

The fiber diameter is important from another point of view, and that isbrashiness. Fibers which are above the diameter of about .0002 inchgenerally feel coarse and brash and the fabrics thereof are irritatingto the skin. However, when the fiber diameter is reduced below thisfigure, all brashiness is eliminated and the fabrics are smooth and havea soft feeling to the skin. 40

Another important feature of the invention which is tied in with fiberdiameter, is the ratio of fiber diameter to yarn diameter. This ratio ofyarn diameter tofiber diameter has a definite bearing upon the degree ofbending to .which the 45 individual fibers will be subjected when thefabric is folded or creased. This ratio should beat least as high asabout 10 to 1, depending upon the fiber diameter itself.

The radius of curvature to which each fiber is 5 subjected when thefabric is folded is the radius of curvature of the yarns themselves,since the yarns are folded over each other, or, at least, the yarnsextending in the transverse direction. Thus the thinner the yarns, thesmaller will be the 55 radius of curvature and the more likelihood offracturing the yarns when the fabrics are folded. The number of fibers,therefore, composing each yarn also has a bearing on the above ratio. 5That is to say, if a large number of fibers go to make up the individualyarns, there will be less likelihood of fracture due to creasing orfolding the fabrics, and conversely, the smaller the number of fibers inthe yarns, the greater will be the tendency of fracture owing to bendingor creasing of the fabrics.

Thus, in order to produce a usable, thin, flexible cloth, it isnecessary to build up the individual yarns with a multiplicity ofindividual fibers having diameters below the diameter indicated.

The number of fibers in each yarnwhich is to be woven or interlaced withother yarns into a textile fabric should have at least about 70 andpreferably more than about 100 fibers. Of course, when plying the yarns,it is the total number of fibers in the final yarn which is important.

In fabricating these yarns composed of a multiplicity of glass fibers,we may use an adhesive or lubricant or sizing which increases the massintegrity of the group of fibers, and inhibits mutual scratching of thefibers and facilitates the handling, winding and unwinding of the yarnupon spools, and various other steps of the process. The sizing orcoating material may be of any suitable type such as wax, oil varnish,shellac, cellulose products or derivatives, resins, plastics, gelatins,agar agar, starch, casein, paraflin, rubber, latex, acetate, arylphosphate, tricresyl phosphate, halogenated hydrocarbons of both theallphatic or aromatic types, or the like.

If desired, the sizing or coating material may be removed after thefabrication, and other types of coating materials may be substituted intheir place if desired. These latter are generally such substances aslubricants, as for example, light oil or the like. The glass fibers mayalso be dyed with any suitable substances to provide the proper colorhues, shades or designs.

The present application is a continuation in part of our co-pendingapplications, Serial Number 704,028, filed December 26, 1933; SerialNumber 82,293, filed May 28, 1936; and Serial Number 105,405, filedOctober 13, 1936, these applications illustrating and describing morefully the methods and apparatus which we may use in order to produce thefine fibers called for in the present application.

Other objects and advantages of the present invention will becomeapparent from the following description taken in conjunction with thedrawings, in which:

Fig. 1 is an elevational diagrammatic view shown partly in section of anapparatus adapted to produce fine glass fibers by means of a gaseousblast, and form them into a sliver or yarn;

Fig. 2 is a fragmentary plan view of a portion of the device illustratedin Fig. 1 showing the fiber collecting means used for forming thesliver;

Fig. 3 is a diagrammatic elevational View illustrating another apparatuswhich may be used for producing long, fine fibers, particularly of thecontinuous fiber type, and forming them into a thread or yarn;

Fig. 4 is a diagrammatic elevational view of an 7 apparatus which may beused to coat the yarn with a suitable sizing or coating material;

Fig. 5 is a diagrammatic elevational view of a winding or spinningdevice adapted to twist the strands or slivers into twisted yarns orcables;

Fig. 6 is a diagrammatic perspective view of a loom adapted tointerweavethe glass fibers into woven fabrics; Fig. '7 is a more or lessdiagrammatic perspective view of a cable yarn composed of yarns twistedin one direction, and which have themselves been intertwisted togetherin the opposite direction to produce a balanced cable yarn; I

Fig. 8 is a diagrammatic view of a braided tubular fabric composed ofbraided glass yarns; and Fig. 9 is a diagrammatic plan view of a knittedIabric composed of glass yarns. The formula heretofore generally used inmechanics for deflection on central loading of a beam is:

deflectronwhere P is the load, 1 the length of span, E the modulus ofelasticity and I the inertia, which for a rod section is 0.05d whered isthe rod diameter. As this equation is applied I to a. glass fiber bybending it into a loop. and pulling the loop down to the point justbefore which it will break, the deflection is' equal to 1/".Substituting now in the above equation and combining constants, we havei which means that the circumference of the loop at breaking isproportional to the square of the fiber diameten. That means that theloopthat can be made from a fiber 1 unit in diameter will be A; as largeas the loop that can be made from a fiber 2 units in diameter. Thesevalues, however, do not tell the complete story for the size of the loopis also a function of the tensile strength which increases markedly asthe fiber becomes smaller so as to permit a still smaller loop to bedrawn. It also happens that E increases slowly as the fiber is drawnsmaller, thus making a further correction in the proper direction. Thus,we have found that the size of the loop that may be drawn, decreaseswith a decrease in the square of the fiber diameter, as a quadraticfunction of the diameter because of the increased tensile strength,andas some other less important function of the modulus of elasticity.

Another significant observation is that the open area of the loopdecreases in turn as the square of the diameter of the loop. Since thearea of the loop determines the yarn diameter over which the fibers ofthetransverse yarns are bent, the area of this loop is extremelyimportant in determining creasability of fabrics and knotability'ofyarns.

We have also noted a marked acceleration in the tensile strengthincrease as the fibers are drawn below .0004 and particularly at orbelow .0002 inch. An equation which we submit for the relation betweentensile strength and diameter is:

where Ts is the tensile strength in thousands of pounds per square inchand d is the diameter expressed in units of ten-thousandths inch.

The presence of this last term has not been known or appreciatedheretofore.

The significance of the above equation may be stated in words as, thetensile strength of glass fibers is equal to the bulk strength of glasswhere fiaws are'numerous, plus the increase in strength due to thereduction of fiaws at the surface of the glass fiber, plus the increasein strength due to the decrease of fiaws in the body of the glass.

We also believe that the surface tension in the fibers at this extremelylow diameter has an effect of maintaining the surface more perfect andmore resistant to stresses.

As a result of the above considerations, we have discovered a criticalvalue infiber diameters for producing successful weavable yarns.Moreover, when the fiber diameter is maintained below .0004 inch andpreferably not more than about .0002 inch, the fibers may readily betwisted, flexed, and compounded into yarns comprising a multiplicity offibers which are free from brashiness or skin irritation. Moreover, thefiber diameter should be maintained below the critical range if it isdesired to produce yarns having a sufilcient number of individual fiberstherein, that is, at least about '70 or preferably more than 100, and

yet produce a yarn which is not bulky but which is notably thin,flexible, pliable, and workable. The fabric is also relatively thin inspite of the large number of fibers composing the yarns.

Referring now more particularly to Figs. 1 and 2, a conventional glassfurnace has been illustrated, having an electrically heated bushing 22,preferably composed of a platinum alloy or platinum metal, forming anoutlet feeder having a plurality of individual orifices 23 arranged atthe' lower end thereof for the emission of a plurality of glass streams.If it is desired, and it has been found practical to do so, the glassmay be melted from cullet or batch material directly in the electricallyheated bushing '22, thus dispensing with the furnace 20.

Spaced beneath the outlet orifices 23 is a blower 25 which is formed intwo parts, separated by a slot 26through which the glass streams flowand are attenuated by gaseous blasts emanating from. a series of jets21.

Below this blower a convenient distance is an endless foraminous surface3 which may be in the form of a screen, mounted upon the rotating drum3|, supported by spokes 32 and rotating upon the shaft 33. As the glassstreams emerge from the bushing 22, they are attenuated into long, finefibers'35 having the desired characteristics, and then are conveyed bythe gaseous blast upon the foraminous surface 30 where they are arrestedand collected into the form of a web 36. Baffles 31 may be adjustablyplaced on each side of the region of the surface 30 upon which thefibers collect, these bafiles 31 serving to conduct all of the fibers 35to the proper region upon the surface 30 where they may be compactlycollected into the form of the web 36. Underneath the surface 30 is asuction box 40, which communicates with a suitable suction blower orother suitable exhausting means 4 the suction box serving to withdrawthe vehicular blast and facilitating the retention of the web 36 uponthe surface 30 as it is being collected and drawn off into the form of asliver or yarn 44.

The drum 3| is driven byany suitable means such as a motor which ismechanically connected to the drum 3| through the pulleys 46, theadjustable speed change box 41, and the belt 48.

After the fibers have been collected in the form of the web 36, they aredrawn off in the general direction of travel of the screen or surface30, although at a higher speed than the peripheral speed of the surface30; and then drawn through a compacting device or trumpet 49 thenthrough suitable folding devices such as the diablo-shaped rolls 50,which serve to compact the web and to fold in the loose edges and loosefibers which may otherwise project outwardly from the sliver M; thenthrough the guide 5|; through the traverse 52 and then over the spool 53into the form of a-package 54. The spool 53 is mounted upon a suitabledrum or shaft 55 which is driven by the motor 56. The mechanical driveconnection silver in which the individual fibers lie predominantly in alongitudinal direction parallel to the sliver, although incompletelyparallel and being mutually intermatted with one another to form acoherent strong sliver which may be processed as desired, as, forexample, by twisting, winding,

spinning, weaving, or the. like. These yarns or slivers may also bedrafted into fine attenuated threads which may then be compounded intoply yarns, balanced yarns, and fine textile fabrics.

Referring now more particularly to Fig. 3, we

have diagrammatically illustrated an apparatus capable of producing ayarn or thread composed of a multiplici y of continuous glass filaments.The glass may be melted in a suitable glass furnace having a suitablebushing 6| at the lower end thereof to feed a multiplicity of glassstreams through a series of outlet orifices 63. The glass streams aremechanically attenuated by means of a rotating spool over which thethread 66 formed by the grouping of the individual fibers together, iswound.

Spaced beneath the bushing 6| is a suitable blower 61, which also may beformed into two parts having a slot 68 therebetween through which theindividual fibers '62 are drawn. The blower 61 serves to direct a blastof cooling gas such as air, or the like, through the jets 69 onto theindividual fibers, chilling them within a short distance of the outletorifices 63. The blasts emanating from the jets 69 also serve to inducea draft of cool atmosphericair over the top of the blower and downthrough the slots, whereby it tends to cool the glass as it emerges fromthe outlet orifices.

The individual fibers '62 may be grouped by means of a suitable devicesuch as that formed by a V-shaped slot 13 having a pad 74 in the groovethereof, over which the fibers may be drawn into the thread 66. Arrangedin conjunction with the pad 14 is a Lubricant reservoir 75 adapted to befilled with a suitable lubricant or sizing or coating material supplybody 16. If the supply body 16 is composed of a thermoplastic substance,such as wax, asphalt, or the like, it may be heated by any suitablemeans such as the burner 11. I

When using a thermoplastic substance or one which requires evaporationin order to harden it over the thread, it may be desirable to expose thethread 66 over a relatively long distance applying heat or drying air tothe same before winding upon the spool 65. Assisting in the'formation ofa neat package which may be readily unwound from the spool 65, is atraverse I8. When winding the thread, however, at extremely high speed,such as 5 to 10 or even 20,000 feet per minute, the traverse may bedispensed with and the thread would directly upon the spool 65.

In producing fine long fibers by means of such an apparatus, we havefound it important to maintain the temperature of the molten glasswithin the bushing 6| in a relatively high range. Temperatures rangingfrom about 2100 F. to about 2500 F. have been found suitable, depending,of course, upon the particular type of glass which is being melted andthe degree of attenuation which is desired. From this relatively hightemperature, which is generally in the neighborhood of about 2200 F. to2400 F., the glass as it is drawn out of the outlet orifices and isattenuated, attains a relatively high speed, at least about severalhundred feet per minute, and preferably more than about 1000 feet perminute, and for most economical results, more than about 5000 feet perminute.

The cooling blasts from the jets 88 serve to chill the glass and permitit to be sufiiciently viscous that it may be drawn down into anextremely fine fiber within an unusually small range below the orifices63.- The glass instead of producing a viscous fiber which is graduallyattenuated into a finer fiber, draws down directly from the molten glassinto a fine fiber form where it is suddenly chilled into that form whileit is still within about an inch or so from the outlet orifice.

The degree of attenuation to which these fibers may be subjected isextremely high, and it is possible to produce fibers having diameters ofabout .0002 inch more or less without difficulty. The diameters of theorifices 63 are also relatively small, and may be about .030 to about.060 inch in diameter, more or less, as desired.

The fibers produced by the methods illustrated in Figs. 1 and 2 and bythe apparatus illustrated in Fig. 3, are not only extremely fine, butare also extremely long, and have strengths ranging in the order ofmagnitude of about 300,000 pounds per square inch as an. ordinarymatter, and in certain instances, much higher and in the order ofmagnitude of about one million to three million pounds per square inch.These fibers are also extremely flexible and are substantially free frombrash .or skin irritation.

The threads formed by these methods of production, may be processedthrough any of the usual textile machines to produce twisted yarns, plyyarns, cables, balanced yarns, and fabrics of any desired type such asknitted, interwoven, or braided fabrics, as brought out more fullyhereinafter.

If it is desired to weave the slivers 40 directly into yarns withouttwisting the same, it has been found preferable to coat the same with asuitabe sizing, and for this purpose the apparatus illustrated in Fig. 4may be used. The sliver 44 is drawn from the spool 53 over the guiderolls and then into the bath 8i of the sizing material within a tank orreservoir 82. For this purpose we have found that gelatin or other sizesmentioned hereinabove are satisfactory.

A roll 83 may be submerged in the bath 8| around which the sliver 44 isdrawn. In order I to remove excess sizing or coating substance, coactingrolls 84 may be arranged over the container 82, these rolls serving as awringer. If desired, the thread or sliver 44 may then be dried in asuitable heating chamber 85 which may be provided with burners or othersuitable heating, means 86. From here the thread or silver 44 may beagain wound upon a spool 81, with the assistance of the traverse 88.

The yarns formed by the mechanism shownin Fig. 3 or Figs. 1 and 2, orthe sized yarns or threads produced by the apparatus in Fig. 4,

may be twisted, either singly or in groups, to

form twisted yarns. a conventional apparatus for this type of twistinghas been shown in Fig. 5, in which one or more spools I00 may feed inthe required number of threads IOI through an eye I02, around the rollsI03 forming a bite for the yarn, then through the eye I04, through .thedrag I05, and then around the rotating spool I01. The drag I00 ismounted upon a traversing means I00 which serves to distribute and windthe thread I M uniformly over the spool I0I,to form a neat package. Thespool I0I is rotated by any suitable means such as the belt I09.

The degree of twist induced by this apparatus may be relatively high ifdesired, as, for example 6 to 12 or more turns per inch; the degree oftwist, of course, being dependent upon the diameters of thefibers andthe number of fibers composing the individual threads which are beingtwisted. We have found'it possible to twist, on conventional twistingapparatus, strands composed of only a few fibers such as only 5 to 10fibers or even less, these fibers having, however, diameters less than.0004 inch, and for best results, less than .0002 inch. V

By intertwisting the fibers into a twisted yarn form, with asuflicientiy high degree of twist, it is possible to overcome theinherent objection to glass fibers caused by their non-stretchability,or tendency not to elongate. Ordinarily the degree of stretch which anyindividual fiber may pos sess before breaking, is extremely small, andeven for fine fibers, is seldom more than one or two, or at the mostabout 3 per cent. Owing to the inherent non-stretchability of thefibers, it has been found substantially impossible to weave them in aconventional loom. As such a warp of yarns composed of glass fibers isbeing fed into the warp of the loom, any stresses or vibrations causedby the loom cause the entire load to be borne by the tightest end; theseloads being frequently sufficient to break an individual yarn or end,before the load can be distributed to the other ends in the warp. Whenthe tightest end breaks, the load is transferred to the next tightestend which also does not have sufi'icient strength to carry the entireload, and it also breaks in turn before the load can be distributedamong the several ends. However, we have discovered that by providingyarn having sufliciently fine fibers, which may be intertwisted asufiiciently high degree, the yarns themselves may possess .a relativelyhigh degree of elongation, in the order of magnitude of about 10 to 30per cent before breakage. The degree of stretch, of course, in thetwisted yarns is also dependent upon the sizes of the yarns compared tothe fiber diameter; the smaller the yarns, the les being the elongationbefore breakage.

In this connection, it is to be noted that the yarns formed from thesliver's produced by the apparatus shown in Figs. 1 and-2, have anespecially high degree of elongation and stretchability, owing to theirparticular structure. The fibers of these yarns are intermatted andinterlaced with one another and are not in substantially completeparallelism and alignment as are the continuous filament yarns formed bythe apparatus shown in Fig. 3. Owing to their inherent intermattednature, these yarnsseem to possess a higher degree of yieldability, andwhen they are twisted into the form of a twisted yarn, the intermattedfibers of the yarn appear to yield and distribute the stresses and loadsinduced in the yarn throughout the yarn as a whole, thus angle.

substantially increasing the total strength and resistance of the yarn.

The twisted yarns produced by the winding apparatus shown in Fig. 5, maybe intertwisted with one another to form balanced yarns, an example ofwhich is illustrated in Fig. '7.

In Fig. 7 two original yarns IIO are intertwisted to the right for asuflicient number of turns as, for example, 6 to 12 turns an inch toproduce the twisted ply yarns I I I, and then two of these twisted yarnsI II are intertwisted to the left for the required number of turns,generally slightly more than half of the original degree of twist toform a balanced cable yarn II2. Balanced yarns or cables of othervarious types may be formed, such as two, three, or four-ply or variousother types of ply yarns or cables, or the like.

Referring now more particularly to Fig. 6, we have diagrammaticallyillustrated a loom which may be used to weave threads or yarns composedof glass fibers. In weaving glass cloths, it is possible to use anydesired construction 'such as plain weave, twill, or manifold others,and in doing so, it is possible to produce cloths having any degree ofhardness which is desired. In other words, we are not limited in weavingglass cloths having the individual yarns of the warp or filler spacedapart from one another in order to provide suificient flexibility andpliability to the materials. On the contrary, it is possible to placethe ends of the warp extremely close together, and to pack the filleryarns tightly into place. The resulting cloth will have excellentproperties of flexibility, strength, foldability, and general resistanceto wear.

In Fig. 6 we have shown the warp II4 wound upon the warping beam I I 5.From here the warp is trained over the whip roll I I6 which ispreferably arranged in such a position that the indi-' vidual ends ofthe warp II4 make contact over a relatively wide are on the surface ofthe whip roll and are turned through a relatively wide We have foundthat this arrangement materially reduces the number of breaks in the.ends by permitting the whip roll to relieve the individual yarns ofunusual stresses and enables the individual yarns to be held at aconstant tension.

The remaining portions of the loom may be of the conventional type, andthus, may comprise the heddles II'l, operating to produce the shed intowhich a shuttle II8 travels, and cloth beam over which the woven fabricis wound.

In weaving glass cloths, we have discovered that the difliculty causedby the non-elongation of the individual glass yarns may be overcome byprovid ing resilient coverings I20, composed of rubber or other suitableyielding material over the warp ing beam II5. A resilient cover I2I mayalso be provided over the whip roll IIS. By the use of this resilientmaterial over the warping beam and the whip roll, and of the arrangementof the whip roll in relation to the warping beam whereby the warp iscaused to turn through a substantial angle, it is possible to maintainan even tension on the individual yarns or ends between the heddles ofthe loom and the warping beam. Thus, as m'brations or pulsations areinduced into the ends by the reciprocatory movements of the.

heddles, the whip roll H6 and the resilient cover therefor I2 I yieldand take up a large portion of these vibrations. Any unusual stresses inthe individual ends may also be relieved by the resilient cover I20 onthe warping beam II5.

We have discovered that when suflicient yarn is wound upon the warpingbeam to weave an entire bolt of cloth, that is, when there are abouteighty yards of yarn per end, the warp on the beam is of considerablediameter and consequent 1y possesses a suflicient resilience andyieldability of its own which may be called upon to relieve any unusualstresses in the individual ends. However, when the beam has run throughnearly the entire weaving operation, and there is little warp left uponthe beam, the resilient cover I20 is adapted to relieve any unusualstresses in the individual ends. Thus, by means of this novelconstruction of loom, it is possible toweave an entire bolt of clothseveral yards in width, if desired, with substantially no breaksthroughout the entire weaving operation.

Various other types of textile fabrics may also be made from our novelyarn or threads, another example of which is illustrated in Fig. 8showing a braided article I25. This braided article is in tubular formalthough, of course, any other type or construction of braid may beused. When in tubular form, it has particular application as a wirecovering or other covering means. The braiding operations may beperformed by any conventional textile machine now in use.

Another example of a textile fabric which we may make using our novelglass yarns, is illustrated in Fig. 9 showing a knitted fabric I26. Theknitting may be done on any conventional machine, and may be made withany desired con struction. We have found it possible to weave directlyfrom glass yarns, various articles such as socks, gloves, sweaters orthe like. The knitted articles may be knitted with a tight construction,if desired, and we have found that such fabrics possess an extremelyhigh flexibility, resilience and stretchability; although when pulledout of shape, they will return to their normal position after thestresses are relieved.

Modifications and variations may be resorted to without departing fromthe spirit and scope of the present invention as defined in the appendedclaims.

We claim:

1. A textile yarn composed of at least forty fine glass fibers havingaverage diameters not more than about .0004 inch, the fibers of saidyarn being twisted in order to produce a yarn of substantialflexibility, mass integrity, strength and stretchability to permitknotting without rupturing said yarn.

2. A glass textile fabric comprising. interlaced textile yarns as calledfor in claim 1.

3. A textile yarn composed of at least forty fine glass fibers havingdiameters not more than about .0003 inch, the fibers of said yarn beingintertwisted in order to produce a yarn of substantial flexibility, massintegrity, strength and stretchability to permit said yarn to be foldedover itself without rupturing said yarn.

I 4. A flexible, closely woven textile fabric capable of being foldedand creased without fracture, which comprises interwoven yarns asclaimed in claim 3. v

5. A textile yarn composed of a multiplicity of fine glass fibers lyingpredominately parallel to the longitudinal direction of said yarn andbeing intermatted with one another in said yarn, the

fibers of said yarn having diameters not more than about .0004 inch, andsaid yarn being twisted able 0! being folded and creased withoutfracture, which comprises interwoven yarns each composed of vamultiplicity of intertwisted fine glass of at least seventy fine glassfibers having diam- V eters not more than about .0002 inch, the fibersof said yarn being intertwisted to produce a yarn of substantialflexibility, mass integrity, strength and stretchability to permit saidyarn to be folded over and wrapped around itseltwithout rupturing 5 saidyarn.

GAMES SLAYI'ER. JOHN H. THOMAS.

